Avaliação da atividade das enzimas NTPDase e acetilcolinesterase em linfócitos de adultos portadores de Síndrome de Down: relação com parâmetros inflamatórios.

Abstract

Down Syndrome (DS) is a chromosomal alteration characterized by the presence of an extra copy of chromosome 21. Subjects with DS exhibit an increased susceptibility to infections and autoimmune disorders. ATP, adenosine, and acetylcholine modulate immune responses and NTPDase, adenosine deaminase (ADA) and acetylcholinesterase (AChE) are important enzymes that control of extracellular levels of these molecules at inflammatory sites. In this study we evaluated the activities of these enzymes, hematological parameters, as well as cytokine levels in samples of DS individuals and healthy subjects. The population consisted of 23 subjects with DS and 23 healthy subjects as a control group. Results showed that NTPDase activity using ADP as substrate was significantly increased in lymphocytes of DS patients in relation to the control group (P≤0.05); however, no alterations were observed on ATP hydrolysis. A significant increase was observed on AChE and ADA activities, respectively, in samples of DS patients when compared to healthy subjects (P≤0.05). In DS subjects an increase in the levels of pro-inflammatory cytokines such as of IL-1, IL-6, TNF-α and IFN-γ, respectively, and a decrease of IL-10 levels, a anti-inflammatory cytokine, were also observed (P≤0.0001). These findings suggest that alterations in NTPDase, ADA and AChE activities as well changes the cytokines levels may contribute to immunological alterations observed in this genetic disorder.